A majority of the commemorative 50 pence coins are composed of cupronickel, but the Royal Mint has also struck such coins in gold and silver on a number of occasions. In many cases, silver piedforts are struck by the mint in addition to their regularly-sized silver counterparts. Like the general issue 50 pence coins of the United Kingdom, all the commemorative issues are heptagonal in shape. The cupronickel and normally-sized silver coins struck between 1973 and 1994 weigh approximately 13.5 grams, while the gold examples minted during the same time weigh about 26.32 grams. Beginning in 1998, the diameter of the commemorative 50 pence coins was reduced from 30 millimeters to 27.3 millimeters. As a result, the masses of the cupronickel and standard silver issues were reduced to 8 grams, the silver piedfort to 16 grams, and the gold to 15.5 grams. Like most British coins produced since the 1952, all commemorative 50 pence coins bear a portrait of QueenElizabeth II on the obverse.